The cause, symptoms and treatments for Alzheimer’s disease
By: Alice Ouyang
We all get old, that goes without me saying it. And the changes that take place in our brain are irreversible. It’s simply a matter of time till we die. All efforts to outlive death will fail. That is depressing but obvious. Exercise and good habits will only buy years, but never infinity. And this might surprise you, but the same applies for Alzheimer’s (or aka: AD)
AD is the number one killer in neurodegenerative diseases. 5~8% of people who are above 65 get Alzheimer’s, 15~20% for those who are 75+ and 25~50% for people above 85. And they all eventually lead to death. If we can live long enough, every single person will die of Alzheimer’s. why don’t we all die of AD? There is only one way to avoid dying of AD, and that is: to die before AD gets you. Not a very good choice huh? So, what causes this? Well, no one fully understands. But there are two culprits that we can be sure of: beta-amyloid proteins and tau proteins. Beta-amyloid proteins form when an enzyme slices up another protein. Once formed, the beta-amyloid proteins clump together and forms plaques. These plaques block up synapses, and therefor disrupt neuron signaling. And they also trigger immunes reactions that cause the neuron to self-destruct. The tau proteins used to work for the neurons, they ensure the tubes that transport nutrition to neurons are straight. But these tau proteins somehow get tangled up and the tubes disintegrate, thus leading to cell death.
It probably sounds a little disturbing to you but, patients with AD have shrunken brains, their vesicles enlarge, the cerebral cortex shrinks, especially the temporal and parietal lobes. The grey matter decreases by 10%. This is very significant in the PFC (prefrontal cortex) and the hippocampus (the brain area associated with memory). This is why the earliest symptoms are memory deficienciesand impaired judgment and logical skills. Then comes the mood swings, repeating things, wandering, losing things and finding daily tasks difficult. In the end the AD gets to the deepest, most treasured memories, their lives will become entirely dependent. And at last, the brain stem can no longer fight against the AD.
There are several ways to diagnose AD. Patients can get a brain scan, but a more affordable approach would be to test cerebrospinal fluid for tau proteins and beta-amyloid proteins. An EEG could also be a way to diagnose AD.
There is no drug that can fully cure AD. There are 5 drugs that the FDA has approved of, however, they only relive some symptoms and slow its progression but they do not really 「cure」 the disease. There is a decrease in Ach in AD patients, so a type of temporary treatment reduces the breakdown of Ach. A possible cure would be a kind of vaccine that can train the immune system against the plaques. There is a potential cure in the autophagy of cell. Autophagy is a basic metabolic way of eliminating nonessential or abnormal substances. This idea was proposed by the researchers of Fudan University. Since we can’t 「cure」 AD, the best way to stay healthy is to prevent it, but since we can’t really prevent it, it’s really delaying AD.
Getting Alzheimer’s is our brain’s ultimate fate. It’s like a path that we are walking down, and some simply die before they reach the ending. But we can push that ending back, not all hope is lost. The first thing to do is to always get enough sleep. you may be tired of hearing this sentence, but during the SWS stage of our sleep, our spinal fluid 「washes」 out the piling beta-amyloid proteins and other metabolic waste. A nutritious diet helps a lot. Studies have shown that a Mediterranean diet can slow aging and improve cognitive abilities. Enough exercise is also important. These are all the obvious preventions, a rather surprising one is cognitive reserve, or in other words, knowledge. Some people show all biomarkers of Alzheimer’s, but symptoms just don’t appear. This is why.The more cognitive reserve you have the more new and complex neuro connections you have. For example, if you only have one synapse about one thing and that synapse is destroyed by AD you will forget that thing for ever, but if you have three different synapses on that thing, even if you lose 2 of them, you still have one memory of that thing, and most times, that is enough. But reviewing old things won’t work. Retrieving old memories won’t help. You have to make new connections.
Alzheimer’s is simply a matter of time.
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